Beck was the main composer for Buffy the Vampire Slayer during seasons 2-4. He later returned to compose for the key episodes "The Gift" and "Once More, with Feeling", though he had signed for the musical earlier before his departure, making him obligated. Notable pieces of Beck's work have appeared on various Buffy soundtrack albums:

Once More, with Feeling
Although Joss Whedon wrote the songs for "Once More, with Feeling", Beck was hired to realise them and provide the score. This album is almost entirely dedicated to this particular episode, but also features three Beck compositions from earlier episodes; "Suite from Restless", "Suite from Hush" and "Sacrifice", from "The Gift".

Buffy the Vampire Slayer: The Score
This release is entirely dedicated to Beck's compositions for the show. Much of the music is from "Graduation Day", "Hush", "Restless" and "The Gift", amongst others. Multiple cues are edited down versions of the original pieces heard on promotional CD's leaked years before.